Service Manual

GSM-204-423
Connecting fibre optic cables
31st Oct 01
Installation & Configuration: Horizon macro outdoor
68P02902W03-A
CONTROLLED INTRODUCTION
Inst. 3–57
Connecting fibre optic cables
Location of
fibre optic
connections
In an installation configuration with more than one Horizon macro outdoor
cabinet, fibre optic connections are used to link the MCUF in the master cabinet
to the extension cabinets. A maximum of three extension cabinets can be added
to the master cabinet.
Connections from the master cabinet are provided by three fibre optic
multiplexers (FMUXs). Two are located integral to the MCUF, and the third is a
separate module located in the slot next to the master MCUF. Additional
redundant modules may be installed for both MCUF and FMUX modules.
Extension cabinets have only a single FMUX, with optional redundancy, for fibre
optic connectivity to the master cabinet.
Tx and Rx data connections to the MCUF and FMUXs are located on the front
panel of each module.
Three different types of fibre optic cable, coloured orange and terminated with
ST fibre connectors, are available for use. These are described in Table 3-5.
Table 3-5 Extension cabinet fibre optic cables
Order
number
Length Description
SVKN1244 5.6 m long connects master cabinet to first extension
SVKN1245 7.6 m long connects master cabinet to second extension
SVKN1246 7.6 m long connects master cabinet to third extension
WARNING Do not look directly into a fibre optic cable or the data
in/out connectors of the FMUX or MCUF, with or without
the use of optical aids. Laser radiation can come from
either the data in/out connectors or unterminated fibre
optic cables connected to data in/out connectors.
Care of fibres
Optical fibre cables contain an inner core, which is a strand of glass coated by a
cladding (sometimes in two layers), and an outer protective sheath which
provides mechanical protection.
The fibre acts as a light waveguide. In order for the link to work correctly light
must be propagated with minimal losses from end-to-end of the fibre. A number
of problems can prevent this from happening, resulting in a potentially faulty link.
Care must be taken to ensure that the conditions that follow are met.